Added new C example for iterator using bitmap

examples/C/Makefile.am

@@ -4,32 +4,33 @@ AM_CFLAGS =  @WARN_PEDANTIC@ @WERROR@
 TESTS = iterator.sh get.sh print_data.sh set.sh keys_iterator.sh multi.sh multi_write.sh \
 	precision.sh list.sh large_grib1.sh get_data.sh sections_copy.sh set_missing.sh
 
-noinst_PROGRAMS       = nearest set_bitmap iterator get print_data set set_missing keys_iterator \
-			set_data mars_param values_check box multi multi2 multi_write precision \
-			set_pv list sections_copy large_grib1 get_data
-bin_PROGRAMS          = points
+noinst_PROGRAMS         = nearest set_bitmap iterator get print_data set set_missing keys_iterator \
+			  set_data mars_param values_check box multi multi2 multi_write precision \
+			  set_pv list sections_copy large_grib1 get_data iterator_bitmap
+bin_PROGRAMS            = points
 
-box_SOURCES           = box.c
-set_data_SOURCES      = set_data.c
-mars_param_SOURCES    = mars_param.c
-values_check_SOURCES  = values_check.c
-nearest_SOURCES       = nearest.c
-multi_write_SOURCES   = multi_write.c
-get_SOURCES           = get.c
-print_data_SOURCES    = print_data.c
-set_SOURCES           = set.c
-set_missing_SOURCES   = set_missing.c
-set_bitmap_SOURCES    = set_bitmap.c
-multi_SOURCES         = multi.c
-multi2_SOURCES        = multi2.c
-keys_iterator_SOURCES = keys_iterator.c
-iterator_SOURCES      = iterator.c
-set_pv_SOURCES        = set_pv.c
-points_SOURCES        = points.c
-list_SOURCES          = list.c
-sections_copy_SOURCES = sections_copy.c
-large_grib1_SOURCES   = large_grib1.c
-get_data_SOURCES      = get_data.c
+box_SOURCES             = box.c
+set_data_SOURCES        = set_data.c
+mars_param_SOURCES      = mars_param.c
+values_check_SOURCES    = values_check.c
+nearest_SOURCES         = nearest.c
+multi_write_SOURCES     = multi_write.c
+get_SOURCES             = get.c
+print_data_SOURCES      = print_data.c
+set_SOURCES             = set.c
+set_missing_SOURCES     = set_missing.c
+set_bitmap_SOURCES      = set_bitmap.c
+multi_SOURCES           = multi.c
+multi2_SOURCES          = multi2.c
+keys_iterator_SOURCES   = keys_iterator.c
+iterator_SOURCES        = iterator.c
+iterator_bitmap_SOURCES = iterator_bitmap.c
+set_pv_SOURCES          = set_pv.c
+points_SOURCES          = points.c
+list_SOURCES            = list.c
+sections_copy_SOURCES   = sections_copy.c
+large_grib1_SOURCES     = large_grib1.c
+get_data_SOURCES        = get_data.c
 
 INCLUDES =  -I$(top_builddir)/src
 

examples/C/iterator_bitmap.c

@@ -0,0 +1,94 @@
+/*
+ * Copyright 2005-2014 ECMWF.
+ *
+ * This software is licensed under the terms of the Apache Licence Version 2.0
+ * which can be obtained at http://www.apache.org/licenses/LICENSE-2.0.
+ *
+ * In applying this licence, ECMWF does not waive the privileges and immunities granted to it by
+ * virtue of its status as an intergovernmental organisation nor does it submit to any jurisdiction.
+ */
+
+/*
+ * Description: How to use an iterator on lat/lon/values and query the bitmap
+ *              for missing values
+ *              (rather than compare each value with the missingValue key)
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <assert.h>
+#include "grib_api.h"
+
+void usage(char* prog)
+{
+    printf("Usage: %s grib_file\n",prog);
+    exit(1);
+}
+
+int main(int argc, char** argv)
+{
+    FILE* in = NULL;
+    int err = 0;
+    double lat,lon,value;
+    int n=0;
+    size_t bmp_len = 0, values_len = 0;
+    char* filename = NULL;
+    long bitmapPresent = 0;
+    long *bitmap = NULL;
+    double *values = NULL;
+    grib_handle *h = NULL;
+    grib_iterator* iter=NULL;
+
+    if (argc != 2) usage(argv[0]);
+    filename=strdup(argv[1]);
+    in = fopen(filename,"r");
+    if(!in) {
+        fprintf(stderr, "ERROR: unable to open file %s\n",filename);
+        return 1;
+    }
+
+    while ((h = grib_handle_new_from_file(0,in,&err)) != NULL )
+    {
+        if (err != GRIB_SUCCESS) GRIB_CHECK(err,0);
+
+        GRIB_CHECK(grib_get_long(h,"bitmapPresent",&bitmapPresent),0);
+        if (bitmapPresent)
+        {
+            GRIB_CHECK(grib_get_size(h,"bitmap",&bmp_len),0);
+            bitmap = malloc(bmp_len*sizeof(long));
+            GRIB_CHECK(grib_get_long_array(h,"bitmap",bitmap,&bmp_len),0);
+            printf("Bitmap is present. Num = %ld\n", bmp_len);
+        }
+        /* Sanity check. Number of values must match number in bitmap */
+        GRIB_CHECK(grib_get_size(h,"values",&values_len),0);
+        values = malloc(values_len*sizeof(double));
+        GRIB_CHECK(grib_get_double_array(h,"values",values,&values_len),0);
+        if (bitmapPresent) {
+            assert(values_len==bmp_len);
+        }
+
+        /* A new iterator on lat/lon/values is created from the message handle h */
+        iter=grib_iterator_new(h,0,&err);
+        if (err != GRIB_SUCCESS) GRIB_CHECK(err,0);
+
+        n = 0;
+        /* Loop on all the lat/lon/values. Only print non-missing values */
+        while(grib_iterator_next(iter,&lat,&lon,&value))
+        {
+            int is_missing_val = (bitmapPresent && bitmap[n] == 0);
+            if (!is_missing_val) {
+                printf("- %d - lat=%f lon=%f value=%f\n",n,lat,lon,value);
+            }
+            n++;
+        }
+        /* Check number of elements in iterator matches value count */
+        assert(n == values_len);
+
+        grib_iterator_delete(iter);
+        grib_handle_delete(h);
+    }
+
+    fclose(in);
+    return 0;
+}